What causes migraines? Study of ‘brain blackout’ offers clues
What causes migraines? Study of ‘brain blackout’ offers clues
The blinding headaches are poorly understood — a mouse study suggests that the content of spinal fluid is a trigger for pain.
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Interesting find, apparently protein levels in spinal fluid vary pretty drastically after an aural migraine (where the pain comes after aura).
They say the aura's are a reaction to total neural activity shutdown, but I have never consciously experienced that before an aura. I would expect to have deja vu after such an event
Brain blackout is kind of a dramatic word. I'm pretty sure the article is trying to refer to cortical spreading depression.
https://www.nature.com/articles/nrneurol.2013.192
This is a wave of decreased activity going across the brain. It's not the whole brain though, just a portion, and it tends to happen more often in the posterior brain than anterior. That's why visual and other sensory auras (posterior brain) auras are more common than motor/weakness auras (anterior brain). The visual aura itself is the spreading wave of decreased activity going across the brain. It happens in primary visual cortex, primarily dealing with lines and colors. Visual space is represented radially on the brain, so it can often be circular. The "fortifications" or lines on the edges some people see come from the fact that it's neurons that deal with line detection. Pain usually follows shortly after, but we aren't exactly sure how that works, and this article was posing a possible mechanism to help link these. The main bulk of the visual aura where it's grey, blurry, and indistinct is the decreased activity itself in the visual cortex. The area can get larger as the wave spreads.
Deja vu or jamais vu have been reported with migraines, though that's a very rare aura in comparison. It's all depending on what parts of the brain are involved with the cortical spreading depression for that migraine aura for that person in terms of what symptom will happen. Deja vu would be more temporal lobe. Temporal lobe is the most common localization for focal epilepsies. So deja vu as a symptom of a neurologic disease would more commonly be seen with seizures (focal seizures are sometimes called auras too, which gets confusing but are inherently different from what is happening in a migraine). But don't worry, most deja vu is nothing to worry about.
Very cool explanation, thanks! I think dramatization is the culprit here, introducing noise to the facts.
Your visualization of a type of visual aura is distinctly different from when I have them, which is very cool because another response tells us they do recognize it! Mine is more in the negative space around the 'aura' you shared, rotating on some pulse-timing (about half of the heart BPM ), counterclockwise (am a right-handed human), like a white bolt lightning-wave circling around the middle, covering about half the circle at any time. I'll try and recreate the visuals sometime.
Thanks again for elaborating on this subject, you expanded my understanding :-).
Absolutely, and they don't have to look the same for sure, or even involve visual parts of the brain at all for some people. I don't get them, but I think the various illustrations of them are quite interesting.
This image is kinda similar to my experience. It starts as a very small spot, often just blocking a letter or 2 of a word I’m reading, then spreads out in an arc or rough circle.
One interesting thing I’ve noticed as I get older (40s), is that if I’m moving over a distinct enough pattern, like a tile floor, the area inside the aura updates slower, or lags behind the surrounding (unaffected) area.
Also as I’ve gotten older, the pain following the aura has thankfully gotten lows severe, and sometimes doesn’t happen.
In my experience the pain after the aura sometimes happens, sometimes not. But it’s usually not severe anyway, just an annoying constant headache that lasts for a while (hours) after that.
I get the feeling that it's still happening to me, just outside my head. A floating migraine, tethered by tired spite.
When I was younger, aura meant I was in for 4-6 hours of intense headache afterwards (aged 14-20s). But it reduced more in my 30s and is rare now in my mid 40s.
Same experience here. I've gone through many superstitions regarding it, like living near heavy pesticide use, eating potatoes, refined sugars, brain tumor...
I think the common shared experience of all of us is none of us can tell with absolute sure what triggers it, but we all naturally look for patterns.
Mine were all very connected to relaxing after a stressful time. Most weekends after working an unnecessarily stressful job. I’ve since changed careers and now they are much less common, and also a bit more random, or it’s possible I’m not identifying stressors in my life as well now.
Same for me as well. Usually now I get what kind of feels like a sore brain muscle the next day? Like if I cough or sneeze it’s like a little sharp pain. That usually lasts about 12-18 hours from the onset of the auras.
I never knew about how CSD spreads but that makes sense. I don't see artifacts with my auras. Generally everything becomes too bright and too loud all at once. I know I'm having a bad one if I start writing backwards (I will write the second letter of every word first) or slurring my speech. Thankfully I don't get super bad ones as much anymore.
Ouf! Lucky for us, both our migraine severity seems to lessen over time. My brother had symptoms more like yours, speech slurring or limb movement impediment. Because theses are also seizure symptoms, we had to go to the first aid a bunch on false alarms, but luckily it was always 'just' a crazy migraine.
My wife doesn’t usually get visual auras but she becomes extremely tired and disoriented shortly before the pain starts. Is this caused by the same mechanism?
For fatigue, I'm not sure. Multiple things are happening that give rise to migraines. But fatigue is commonly reported by people before a migraine starts.
https://americanmigrainefoundation.org/resource-library/timeline-migraine-attack/
I've never had a migraine headache, but my wife gets them like three or four times a year, usually pieces by a visual aura (and sometimes if she just goes into a dark, quiet room, she only gets the aura). She always described it as an "electric caterpillar" crawling from the side. I was glad she had told me about it in detail because several years ago I got one, and that's the only reason I knew what was happening. Mine wasn't as colorful as what she described, but otherwise the same.
Here's a short video simulating one, and it's very similar to my experience (and, apparently, hers).